A typical wired audio headset has a “tip, ring, ring and sleeve” (TRRS) connector or plug at the end of its cable, that connects with a mating socket or jack of an electronic audio host device such as an iPhone™ mobile device or an iPod™ portable media player. The TRRS connector, also referred to as a stereo connector, has four conductive contacts (generically referred to as “pins” here) to pass the following signals starting with the tip: left speaker channel (1), right speaker channel (2), microphone (3), and a shared ground or reference (4). For certain consumer markets, the ground signal is assigned to the sleeve contact (pin 4), while the microphone signal is at the ring contact (pin 3). However in other markets, those two signal assignments are reversed. Also, with headsets that only support stereo listening with no microphone, pins 3 and 4 are sometimes shorted together as a single ground contact. The host device should be able to automatically determine what type of headset has been connected to its audio jack, and then route its internal signal paths to the correct pins of the jack.